The document US-7 163 355 B2 describes a foundation of this type, in which each leg and its guide are equipped with a device for relative movement with multiple cylinders and racks.
When the foundation, or complete wind turbine reaches its site of operation, these movement devices make it possible to move each leg down until it makes contact with the seabed, and then raise the platform to the desired height above sea level.
This design therefore requires legs with complex structures and numerous cylinders, which are only used during installation on site and then left in place.